Method for filling a collapsible container



Feb. 21, 1967 R, GREENLEE 3,304,963

METHOD FOR FILLING A COLLAPSIBLE CONTAINER Filed Feb. 20, 1964 2 Sheets-Sheet l Ilv Il 95 fN-- 31 w *Q m Ql (QW h Q w N QN QQ l V NVENTOR. /L/df/"g .7?. @raaf/(Zee,

Feb. 21, 1967 H. R. GREENLEE 3,304,963

METHOD FOR FILLING A COLLAPSIBLE CONTAINER Filed Feb. 20, 1964 2 Sheets-Sheet 2 Q INVENTOR Har/jg ,19. reen/ee.

United States Patent O 3,304,963 METHOD FOR FILLING A COLLAPSIBLE CONTAINER Harry R. Greenlee, Detroit, Mich., assigner to Chrysler Corporation, Highland Park, Mich., a corporation of Delaware Filed Feb. 20, 1964, Ser. No. 346,204 6 Claims. (Cl. 141-4) This invention relates generally to collapsible containers capable of being internally pressurized, such as life rafts, shelters, life belts or collapsible boats and more particularly to a novel method and apparatus for inilating such collapsible containers.

According to the prior art, pressure bottles containing compressed carbon dioxide, CO2, are employed for inflating life rafts. In order to conserve space, the carbon dioxide is usually compressed and contained Within the bottle in a liquified state. Such pressure bottles of the prior art require, under most favorable conditions, approximately forty seconds to suciently inflate a life raft having a capacity of containing approximately 39.0 cubic feet of gas. In the reduced temperatures of Arctic waters this inflating time is increased to approximately two minutes due to such factors as freezing of the CO2 about the pressure bottle discharge orifices (thereby reducing the effective ow area therethrough) and a reduction in the discharge pressure of the CO2 which is a natural consequence of its reduced temperature because of environmental conditions.

Even though forty seconds to two minutes may appear to be insignificant it becomes, in actuality, a-n excessive span of time when one considers that in the frigid temperatures of, for example, the Arctic waters a person cannot remain in the water for any length of time appreciably greater than fifteen seconds and still survive.

The pressure bottles of the prior art cannot be made to inflate life rafts any more rapidly because the inating time is dependent on the volume and pressure of carbon dioxide gas within the life raft and the rate at which the liquid carbon dioxide is converted into a gas is depe-ndent on both its temperature and pressure within the bottle. Therefore, it becomes apparent that the lower the environmental temperature, and hence the temperature of the liquid Carib-on dioxide, the longer it will take for the conversion of liquid carbon dioxide to its gaseous state.

Attempts to offset the eifect of low temperature by increasing the pressure of the liquid carbon dioxide have not proven to be successful because the resulting increased velocity of the carbon dioxide being emitted into the life raft causes the formation of ice in and about the pressure bottle discharge orifice which in turn reduces if not effectively terminates the flow of carbon dioxide therethrough.

Accordingly, an object of this invention is to provide a novel and improved method of inflating a collapsible container such as a life raft.

Another object of this invention is to provide a novel and improved apparatus for practicing said improved method.

Other more specific objects and advantages of this inve-ntion will become apparent when reference is made to the following description and accompanying drawings wherein:

FIGURE l is a plan view of a life raft or inflatable boat illustrating the manner in which a pressure vessel, constructed in accordance with the teachings of this inventio-n, is employed in connection therewith;

FIGURE 2 is an enlarged longitudinal cross-sectional view of the pressure vessel shown in FIGURE l;

FIGURE 3 is a fragmentary view taken generally on the plane of line 3 3 of FIGURE 2 and looking in the direction of the arrows;

Patented Feb. 2l, 1967 FIGURE 4 is an enlarged fragmentary view taken generally on the plane of line 4 4 of FIGURE 2 and looking in the direction of the arrows;

FIGURE 5 is a fragmentary cross-sectional view taken on the plane of line 5 5'- of FIGURE 4; and

FIGURE 6 is a fragmentary cross-sectional view taken on the pla-ne of line 6 6 of FIGURE 5.

Referring now in greater detail to the drawings, FIG- URE l illustrates an inflated life raft 10 equipped with a pressure vessel 12, constructed in accordance with the teachings of this invention, which is operatively connected thereto as -by a suitaib-le fitting 14.

FIGURE 2, a longitudinal cross-sectional view, illustrates the pressure vessel 12 as Ibeing comprised of a tank 16 having a generally cylindrical wall structure 18 capped by generally hemispherical headers or end members 20 and 22 which are preferably welded thereto. Reinforcing ring members 24 may be provided at each end to facilitate the joining of the headers to the cylindrical Wall struct-ure 18.

A length of tubing 26, closed at one end 27 as by suitable capping means 28, is coiled within the tank 16 in a generally helical pattern. Each ring or coil of tubing 26 is integrally bonded, as by brazing, to its adjacent coils and to the inner surface 30 of the wall structure 18 so that the tubing, in addition to providing a storage compartment for pressurized uid, serves to strengthen the wall structure 18.. vThe other end 32 of tubing 26 is connected with chamber 34 which comprises a portion of the valving means and conduitry carried by valve housing 36.

Housing 36 has an inlet conduit 38 formed therein which is i-n communication with chamiber 34. A check valve 40, contained generally within chamber 314, is resiliently urged into sealing engagement with a seating portion 42 about conduit 38 by a spring 44. An externally threaded portion 48 formed on housing 36, generally about conduit 38, permits the connection thereto of a suitable source, or sources, of pressurized uid.

A second chamber 5-2 formed in housing 36 contains a valve 54 which is resiliently urged by a spring 55 into sealing engagement with a seat portion 56 formed generally about a passageway 58. Snap rings 46 may be provided in both chambers 34 and 52 as abutments for springs 44 and 55.

Housing 36 is also provided with an internally threaded portion 60 which engages and receives an externally threaded portion 62 of a plunger housing 64. The plunger housing, also illustrated in FIGURE 3, may be comprised of an enlarged generally cylindrical head portion 66 having a transverse slot 67 formed .therethrough which slot partially receives an actuating cam 68 and a control rod 70 which is connected to cam 68 by means of a pivot pin 71.

An annular seal 72 tightly contained between housings 36 and 64 prevents leakage therebetween. Plunger housing 64 also has a cylindrical opening 74 lformed therein which receives a piston-like plunger member 76 provided with an annular seal 78 received in a peripheral groove thereof. An axial extension 80 may be formed on plungei 76 so as to have an end 82 in relatively close proximity to valve 54.

Hou-sing 36 is also provided with a laterally extending projection 84 having a conduit portion 86 formed therethrough, communicating with passageway S8, and an eX- ternally threaded portion 88 which threadably engages a cooperating internally threaded portion of tting 14.

The entire housing 36 may be received through aperture 90, formed in end member 22, until shoulder 92 of housing 36 abuts against the exterior surface of member 22. Subsequently, a snap-ring member 94 may be inserted in a cooperating peripheral groove of housing 36 so as to provide an abutment against the movement of housing 36 outwardly from the end member 22. All of the cooperating members, that is, the snap ring `94, housing 36 and shoulder 92 are preferably joined to each other as by welding or brazing in order to secure each to the other and to eliminate the possibility of any leakpassages existing therebetween.

Header 20 is provided with another inlet valve assembly 96 which is received through an aperture 98 and secured therein as by brazing or welding. A check valve 100, contained generally within chamber 102, is resiliently urged by a spring 104, seated as against another snap ring 46, into sealing engagement with a seat formed generally about conduit 106. An outer threaded portion 108 provides means whereby said conduit 106 can be brought into communication with a source 110 of pressurized fluid.

FIGURES 4 and S illustrate, in an enlarged view, end 27 of tubing 26 and the capping means 28 carried thereby. The capping means is comprised of a disc-like member 112 having a peripheral portion 114 retained by the end of the tubing 26 so as to be in sealing engagement therewith. A centrally disposed portion 4116 is preferably of generally spherical configuration blending into the peripheral portion 114. A plurality of grooves 118 formed in the outer surface of member 112 radiate outwardly from the center so as to form a generally spoke-like pattern as viewed in FIGURE 4.

Member 112 may be secured to the end of tubing 26 by first forming a counterbore-like portion in the end of tubing 26 (indicated generally by the phantom lines 120 in FIGURE 5), inserting the member 112 and subsequently spinning the end of the tubing over the peripheral portion 114 to assume the configuration illustrated in FIGURE 5.

The capping means 28 is, as will become apparent, intended to fail at a predetermined operational condition. Member 112 is preferably formed of a material which upon failure does not exhibit a tendency to shatter but rather a tearing characteristic. Gold, aluminum and copper (and alloys thereof) are but a few of the materials from which member 112 could be formed. Grooves 118 are provided in order to form areas of reduced crosssectional thickness thereby forming areas of localized stresses and a means of controlling, to a great extent, the type of failure which member 112 will experience when such failure thereof is required.

Operation of invention Inlet valve assembly 96 is operatively connected to a suitable source 110 of pressurized dry air or d-ry nitrogen by means of a conduit 122. A throttling valve 124 may be serially connected in conduit 122 and a pressure gauge 126 may be provided so as to communicate, by means of conduit portion 128, with conduit 4122 downstream of valve 124. Valve 124 is then opened and the air and/or nitrogen is ladmitted into the interior chamber 130 of tank 16, as defined generally by the wall structure 18 and end members 20 and 22, until a pressure of, for example 2000 p.s.i. is attained within said chamber 130. Further admission of air and/or Initrogen is prevented by closure of valve 124 .after which conduit 122 may be disconnected from inlet valve assembly 96. Outward flow of the pressurized air and/ or nitrogen through conduit 106 is, of course, effectively prevented by check valve 100.

Inlet conduit 38 of valve housing 36 may then be operatively connected to a suitable source of liquified carbon dioxide (CO2) so as to ll at least a major portion of chamber 132, defined generally by the interior of coiled tubing 26, with said liquified carbon dioxide.

The liquified carbon dioxide is pressurized within chamber 132 to about, for example, 4000 p.s.i. Such pressurization is preferably accomplished by the admission to chamber 132 of pressurized dry air and/or dry nitrogen. This, of course, can be achieved by operatively connecting inlet conduit 38 to a suitable source '134 of pressurized air and/ or nitrogen by means of conduit 136 which has a valve 138 and gauge 140, similar to valve 124 and gauge 126, respectively, associated therewith. Reverse flow through conduit 38 is effectively precluded by check valve 40. In such situations where the carbon dioxide in chamber 12 is pressurized by the admission thereto of pressurized dry lair and/or dry nitrogen, it should be apparent that when capping member 112 is caused to become open, as su-bsequently described, both the carbon dioxide and such pressurized gas within chamber 132 will lact as a second flow of an intlatng medium, which in effect is a mixture of gases, directed to the collapsible container.

After filling of chambers and 132 is completed, suitable closure caps (not shown) may be provided so as to respectively engage threaded portions 108 and 48 in order to -seal passages 106 and 38 from the ambient atmosphere.

Now, let it be assumed that the pressure vessel 12 is connected to fitting y14 as illustrated and that capping member 112 is designed to fail when a pressure differential of 3500 p.s.i. is experienced thereacross. As actuating rod 70 is moved upwardly (as viewed in FIG- URE 2) the motion is transmitted through pivot pin 71 to cam 68 which in turn rotates counter-clockwise about pivot 144 carried by housing 64. Such rotation of cam 68 causes plunger piston 76 and rod 80 to move to the left thereby abutting end 82 against and moving valve 54 off seat 56.

The pressurized air and/or nitrogen contained within chamber 130 is thereby allowed to pass through chamber 52, conduit 58 and conduit 86 into and through fitting 14 and into the life raft 10. As the air and/ or nitrogen thusly passes into the life raft, the pressure within chamber 130 continually -diminishes until a pressure of 500 p.s.i. is attained therein at which time a pressure differential of 3500 p.s.i. exists across member 112. Consequently, capping member 112 fails thereby admitting the pressurized liquid carbon dioxide from chamber 132 into chamber 130 where it commingles with the air and/or nitrogen remaining therein and Icontinues to flow through fitting 14 into the life raft.

The invention as described provides two stages of inflation the first of which could be referred to as preliminary inflation. That is, the relatively low pressure air and/or nitrogen gas contained within chamber 130 is used to quickly inflate the life raft to a pressure of approximately 1.0 p.s.i. which is suflicient to enable boarding of the raft. The inflation of a raft, having approximately 39.0 cubic feet gas capacity, to this boarding pressure by use of a pressurized dry gas can be accomplished within ten seconds or less. Prior art pressure bottles, under like conditions, require approximately forty seconds.

The second stage of inflation is that necessary to achieve a fully inflated condition of the raft which exists when the raft is inflated to a final pressure of approximately 1.75 p.s.i. to 2.00 p.s.i. It should be appreciated that since the object is to achieve boarding pressure in the least possible time, the subsequent time required to achieve a ful-ly inflated condition `of the raft is of secondary importance Accordingly, the invention employs a gas, such as dry air or dry nitrogen, for initial rapid inflation of the life raft to a boarding pressure. By using the dry gas the occurrence of ice formation at the discharge orifice of the pressure vessel is precluded. This is in contrast to the prior art which employs, almost exclusively, liquid carbon dioxide for accomplishing inflation. Attempts by the prior art to decrease the time required to attain boarding pressure by increasing the pressure of the liquid carbon dioxide have not proven successful because the resulting increased velocity of carbon dioxide causes a formation of ice about the discharge orifice. Such ice formation, in

turn, brings about a substantial reduction in the volume rate of fiow of carbon dioxide and sometimes results in a nearly total termination of further liow.

The invention as herein disclosed provides a pressure vessel having two distinct chambers one of which contains Ia dry gas at a relatively low pressure, While the second chamber contains, at a relatively high pressure, a liquified gas and possibly another pressurized gas or gases. The two chambers are separated from each other by valving means responsive to the `attainment of a predetermined pressure differential therea-cross created by the pressurized gases within said chambers.

In the embodiment disclosed the pressure responsive valving means is in the form of a discalike member 112 made in a configuration which will `fail in a tearing fashion a-s contrasted to `one that is frangible to the degree resulting in fragmentation thereof upon failure. However, a highly frangible disc may nevertheless be suitable in certain situations wherein the resulting fragments, as may occur upon failure of the disc, do not present a threat to the continued successful operation ofthe associated structure.

Although not spe-cifically disclosed, other valving arrangements could be employed in practicing the invention. The primary criteria, regardless ofwspecific valving arrangements or means employed, is that communication between the two pressurized chambers is established upon the attainment of a predetermined pressure differential between the two pressurized chambers of the pressure vessel.

Even though only one embodiment of the invention has been disclosed and described it is apparent that other embodiments and modifications `of the invention 4are possible within the scope of the appended claims.

I claim:

1. A method of infiating a collapsible container comprising the steps of directing a first flow of dry air to the interior of said container from a first source wherein said dry air is pressurized to a first pressure, maintaining said ow of dry air to said interior until the pressure of said dry air within said first source decreases to a second pressure, directing a second fow of carbon dioxide through said first source to said interior of said container from a second source wherein said carbon dioxide `is pressurized to a third pressure substantially greater than sa-id first pressure, and maintaining said second iiow until said collapsible container is inflated to the degree causing said interior to attain at least a predetermined fourth pressure.

2. A method of inflating a collapsible container cornprising the steps of directing a first flow of nitrogen to the interior of said container from a first source wherein said nitrogen is pressurized to a first superatmospheric pressure, maintaining said flow of nitrogen to said interior until the pressure of said nitrogen within said first source decreases to a second pressure, directing a second fiow of carbon dioxide through said first source to said interior of said container 'from a second source wherein said carbon dioxide is pressurized to a third superatmospheric pressure substantially greater than said rst pressure, and maintaining said second flow until said collapsible container is inflated to the degree causing said interior to attain at least a predetermined fourth pressure.

3. A method of iniiating fa collapsible container comprising the steps of directing Ia rst iiow of nitrogen to the interior yof said container from a first source wherein said nitrogen is pressurized to a first superatmospheric pressure, maintaining said flow of nitrogen to said interior until the pressure of said nitrogen within said first source decreases to 4a second pressure, directing a second flow comprised of nitrogen and carbon dioxide through said first source to said interior of said container from a second source wherein said carbon dioxide and said nitrogen within said second source are pressurized to a third superatmosp-heric pressure substantially greater than said first pressure, 'and maintaining said second flow until said collapsible container is inated to the degree causing said interior to attain at least a predetedmined fourth pressure.

4. A method of infiating a collapsible container comprising the steps of directing a r.first flow of dry air to the interior of said container from a first source wherein said dry air is pressurized to a firs-t superatmospheric pressure, maintaining said flow of dry air to said interior until the pressure of said dry air within said -first source decreases to a second pressure, directing a 'second flow comprised of dry air and carbon dioxide through said first source to said interior of said container from a second source wherein said carbon dioxide and said dry Iair within said second source are pressurized to a third superatmospheric pressure substantially greater than said first pressure, Iand maintaining said second ovv until said collapsible container is inflated to the degree causing said interior to attain at least a predetermined fourth pressure.

5. A method of inliating a collapsible container comprising the steps of directing a first fiow of dry gas other than carbon dioxide to the interior of said container from a first source wherein said dry gas is pressurized to a first pressure, maintaining said flow of dry Igas Ito said interior until the pressure of said dry gas within said first source decreases to a second pressure, directing a second fioW comprised of dry gas and carbon dioxide through said first source to said interior of said container from a second source wherein said carbon dioxide and said dry gas within said second source are pressurized to a third pressure substantially greater than said first pressure, and maintaining said second flow until said collapsible container is infiated to the degree causing said interior to attain at least `a predetermined fourth pressure.

6. A method of inflating a collapsible container comprising the steps of directing a first iiow of dry gas other than car-bon dioxide to the interior of said container from a first source wherein said dry gas is pressurized to a first pressure, maintaining said flow of dry gas to said interior until the pressure of said dry Igas within said first source decreases to a second pressure, directing a second fiow of carbo-n dioxide through said first source to said interior of said container from a second source ywherein said carbon dioxide is pressurized to a third pressure substantially greater than said first pressure, and maintaining said second flow until said collapsible container is inflated to the degree causing said interior to attain at least a predetermined fourth pressure.

References Cited by the Examiner UNITED STATES PATENTS 2,341,618 2/ 1944 Humphreys 141-100 2,444,717 7/1948 Allen 141-19 X 2,826,337 3/ 1958 Ford et al 222-3 2,875,792 y3/ 1959 Moyer 141-4 3,117,424 1/ 1964 Hebenstreit 222-3 3,122,181 2/1964 Hebenstreit et al 141-4 3,180,373 4/ 1965 Hebenstreit 141-4 FOREIGN PATENTS 903,876 8/1962 Great Britain.

LAVERNE D. GEIGER, Primary Examiner.

E. I. EARLS, Assistant Examiner. 

1. A METHOD OF INFLATING A COLLAPSIBLE CONTAINER COMPRISING THE STEPS OF DIRECTING A FIRST FLOW OF DRY AIR TO THE INTERIOR OF SAID CONTAINER FROM A FIRST SOURCE WHEREIN SAID DRY AIR IS PRESSURIZED TO A FIRST PRESSURE, MAINTAINING SAID FLOW OF DRY AIR TO SAID INTERIOR UNTIL THE PRESSURE OF SAID DRY AIR WITHIN SAID FIRST SOURCE DECREASES TO A SECOND PRESSURE, DIRECTING A SECOND FLOW OF CARBON DIOXIDE THROUGH SAID FIRST SOURCE TO SAID INTERIOR OF SAID CONTAINER FROM A SECOND SOURCE WHEREIN SAID CARBON DIOXIDE IS PRESSURIZED TO A THIRD PRESSURE SUBSTNTIALLY GREATER THAN SAID FIRST PRESSURE, AND MAINTAINING SAID SECOND FLOW UNTIL SAID COLLAPSIBLE CONTAINER IS INFLATED TO THE DEGREE CAUSING SAID INTERIOR TO ATTAIN AT LEAST A PREDETERMINED FOURTH PRESSURE. 